


Little Monster

by FantasySpices



Category: Undertale
Genre: Cuteness overload, F/F, F/M, Fluffiness, Love, Nightmares, Other, Papyrus is dating Mettaton, Regret, Sans is a single father, parenting, self hate
Language: English
Status: In-Progress
Published: 2016-01-13
Updated: 2016-01-13
Packaged: 2018-05-13 20:22:04
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,695
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5715847
Author URL: https://archiveofourown.org/users/FantasySpices/pseuds/FantasySpices
Summary: <blockquote class="userstuff">
              <p>This is literally a "What if..." to my "When I Come Back to You" story if Ryou died shortly after Aiden was born. I don't plan on making this too long, but *shrugs*<br/>I enjoyed thinking this over and writing it so...enjoy ~</p>
            </blockquote>





	Little Monster

“Never forget the past Sans…never forget what good we’ve done…”  
Her voice echoed in the walls of his mind, her last words to him before she slipped away. How could he forget? Her last moments were burned into the very atoms in his body. He rolled onto his side and took a deep breath, clutching her hoodie to his chest…it still smelled like her. He nuzzled into its fabric and let out a shaky breath. He missed the way she smiled, missed her laugh, her lips…her love struck pink eyes…he missed her. But the cosmos took her away…far away from him, yet closer than ever before. He had absorbed her soul; her very essence lived within him.  
Sans could see the faint purple glow of his eyes now, the fiery mist forming around him in his agonizing moment. He cursed; sitting up on his bed he folded her hoodie and placed it under his pillow again. He stood up and yawned, “Shit…” He mumbled stretching, feeling his bones readjust with a satisfying popping sound. He pulled his hood on his head and walked to his bedroom door slowly, he still felt the grogginess of sleep holding him down. Just as his hand reached for the knob Sans heard a thud…then the wailing of a small child from Papyrus’s room.  
With lightning speed Sans was in the room and scooped the sobbing child in his arms, “Aiden? Are you okay? Where does it hurt buddy?”  
Aiden continued to wail but managed to place a tiny hand to his head. Sans looked over his child’s head, fluffing Aiden’s black hair a bit as he looked, “Nothing looks broken,” He looked around once more to be sure. “You’re not bleeding. Nope, you’re okay, but I’m sure you’ll have a little lump on your head.” Sans held Aiden to his chest until he managed to stop sobbing and was reduced to quiet sniffling. Sans set him on his feet and gave him a stern look, “I thought I told you not to jump off the bed like that.” Aiden was five now, he was a beautiful child with pale white skin, black hair, and bright cyan blue eyes…eyes that looked so much like Ryou’s.  
Aiden wiped his eyes with his sleeve and looked innocently at his father, “I’m sorry daddy.”  
Sans’s eyes softened and he sighed, smiling, “Do you wanna go to Grillbyz for breakfast?”  
Aiden’s eyes went wide and a big smile spread over his face, “Yay! Gwillies!”  
Sans bit the urge to laugh, Aiden’s speaking skills needed improvement, but that was what school was for. Aiden was about to go to school for the first time already, he was growing up too fast. “Alright, saddle up kiddo.” Sans chuckled.  
Aiden scurried to the closet and grabbed his shoes. Sans couldn’t help smiling as he watched Aiden sit on the floor, carefully undo the laces, then study the shoe to make sure the correct one was going on his feet. He pulled them on and then looked to Sans. He was about to help him tie the laces but before he could move Aiden began tying the bow and pulling the strings…he put on his shoes by himself.  
Aiden looked proud of himself as he bounded up to his dad with a big smile, “I did it!”  
Sans chuckled, “Great job, buddy! You did it, all by yourself!” Sans turned away a moment to wipe a tear forming in his eye. When he turned back he picked up his son and placed him under his arm, “Come on, let’s go eat.”  
Aiden was giggling as Sans bounded for the front door. Setting his son down Sans grabbed Aiden’s little blue and white parka and handed it to him, “Think you can put this one on by yourself?”  
Aiden gave a quick nod and took it in his tiny hands. He fumbled with it for a few minutes until he found the sleeve holes. He pulled it on, then fumbled with the zipper. After about a minute Aiden looked up at Sans, he could tell Aiden was very frustrated. Sans used his magic to pull the zipper up, making Aiden gasp in surprise. Sans felt it then, laughter bubbled up as he took in the sight of Aiden’s surprised expression. He laughed, “What’s wrong buddy?”  
Aiden looked up, “Did you see it go up, daddy?” Aiden’s voice was quiet but filled with excitement.  
“I sure did.” Sans knelt down and let Aiden crawl onto his back. “You ready?”  
Aiden pat Sans’s head with a giggle, “Fluffy.”  
Sans took that as a yes and headed out the door.

Aiden bounced in his booster seat, his eyes scanning the room with curiosity. Sans had grown so fascinated with him, he wondered if all human children were like this; energetic, excited, so fascinated with everything going on around him. Sans remembered Papyrus being excitable, but never like this. Though, Aiden was shy around people he didn’t know, but Sans knew that was normal. What wasn’t normal was that Aiden’s magic had yet to be seen. He wondered if Aiden would be a late bloomer like his mother.  
A few moments later Grillby came back with Aiden’s breakfast. Grillby had happily taken on the role of “Fire Uncle” after Aiden had gotten to know him, and Grillby always loved having him around. He set the plate before Aiden, a plate with a pancake in the shape of a bear with chocolate chip eyes and a whip cream mouth, some scrambled eggs, and two small pieces of bacon. Aiden’s eyes were wide with awe and Sans could’ve sworn he heard his little stomach growl.  
“Thanks Grillby.” Sans chuckled as he watched his son grab the ketchup bottle and begin to pour ketchup all over his breakfast.  
Grillby chuckled, a sound that was barely audible through the noise of the restaurant, “So much like you, isn’t he…” Grillby’s voice was low, crackling like a fire.  
Sans chuckled, “What can I say? Ketchup runs deep in our veins.” He gave Grillby a sly look.  
Grillby shook his head, “That was awful Sans…”  
Sans feigned offense, “Excuse me, I thought that joke was extremely humerus!”Sans turned his attention to his son’s plate, and smiled. He took a butter knife and Aiden’s fork and began to cut the pancake up into small pieces, “There ya go.” Sans said and handed Aiden the fork.  
Aiden began to dig in, his face happy as he ate. Before long the plate was empty and ketchup lined Aiden’s cheeks, “Nummy…” Aiden mumbled happily then hiccupped.  
Sans laughed, “Looking good.” Sans laughed taking a napkin to begin wiping Aiden’s face. He fussed, trying to turn his head away but Sans was quick to clean him up. Aiden pouted at him and Sans shrugged, “What? Were you saving it for later?”  
Aiden’s pout turned to a smile and he giggled, “No.”  
Sans was careful not to touch the goose egg forming on his son’s head and ruffled his hair, “Your head still hurt?”  
Aiden shook his head, “Better.”  
Sans nodded, he felt eyes on him and he turned to see a number of female patrons glancing his way. He could hear their hushed conversations clearly, every one of them gushing over how great of a father he was being. Sans blushed and looked away, “I’m doing my best…” He murmured to himself and then looked back to his son who was watching him curiously. “You ready to go see Undyne?”  
Aiden nodded with a determined expression, “Ready for trains!”  
Sans snorted, “I think you’re still a little too young for training, kid.” Seeing the obvious disappointment on his son’s face Sans continued. “But you’ll be in school soon, and once you show me you’re working hard I’ll talk to Undyne about training.”  
Aiden’s eyes lit up and he looked excited again, “School!”  
Sans nodded, “Yeah, just a few more weeks and you’ll be all ready for your first day.” He raised his arm and Aiden wiggled out of his booster seat to hug Sans. When Sans was ready he helped Aiden down to his feet and took his hand. “Alright kid, let’s get to Undyne’s before it gets any later.”

Aiden was riding on Sans’s shoulders, his arms clutching Sans’s head to keep from falling off. Sans had to admit, being a father was great. Aiden was always smiles, giggles, and a whole lot of determination…he just didn’t know the difficulties that came with being a parent, especially taking care of him alone. Feeding, clothing, teaching, and just being there for Aiden hadn’t been the easiest thing to do, but once Sans tapped into his newfound determination, he was able to be so much more than just Aiden’s dad, he was his best friend.  
“How you doing up there, buddy? See anything?”  
Aiden made a humming noise as he looked around, “Shiny.” Aiden pointed ahead to the glittering crystals on the cave walls, ceiling, and floor.  
“You like those shiny crystals, huh?” Sans chuckled and knelt down to pick a blue crystal out of the dirt and dusted it off. He looked it over a moment before reaching up to hand it to Aiden. “Here, keep it.”  
Aiden took it with sparkling eyes and gasped, “So pretty!”  
They walked through Waterfall until they arrived at Undyne’s house. Papyrus, Undyne, Alphys, and Mettaton were gathered outside, talking about something when Sans walked up the path. “Yo.” Sans greeted. He bent down to let Aiden down off his back.  
“AH, THERE YOU ARE SANS! WE WEREN’T SURE YOU WERE STILL COMING OR NOT, BUT I AM HAPPY TO SEE YOU ARE HERE!” Papyrus looked down as Aiden ran up to him with a big happy smile. “AND HELLO TO YOU, AIDEN!” He knelt down to wrap his arms around the child.  
“Well don’t hog him all to yourself darling.” Mettaton smiled at Papyrus and held out his arms. “Come give Ton Ton a hug.”  
Aiden gave Papyrus a squeeze before leaping to Mettaton’s arms. Mettaton looked almost star struck as he snuggled the small child. Undyne grinned, “Hey squirt.” She said then ruffled his head. Aiden let out a whimper of pain and Sans caught Undyne’s arm.  
“Aiden fell and hit his head this morning, he’s okay but he has a painful lump on it.” He said calmly.  
Undyne’s eyes widened, “Sorry kid, I didn’t know, are you alright?”  
Aiden nodded and turned to reach for Undyne, to which Undyne softened up and pulled Aiden from Mettaton. Sans sighed and leaned against Undyne’s house while Aiden was passed around and cuddled by their friends. He took a deep breath then released it, he loved seeing everyone so happy but something always twisted in his chest looking at them…like someone was missing.  
He felt his pant legs get pulled and he looked down to see Aiden looking up at him with a small smile. Sans’s chest tightened, he looked too much like his mother, “Heh…whatcha up to, huh?”  
“Amine!”  
“You mean anime?” Sans asked kneeling beside him.  
Aiden nodded, “Alphies wants to watch ami…amin…anime.” Aiden struggled to say but pulled through.  
This child was threatening to kill Sans with his cuteness, “You want to watch too?”  
Aiden nodded and took Sans by the hand, “You too daddy!”  
Sans looked up at his friends who were all smiling at him. Sans rolled his eyes and smiled down at Aiden, “Sure, let’s go watch some amine-“ Sans paused and cleared his throat. “Anime…jeez kid, now you got me saying it.” He laughed.  
As everyone ran inside Papyrus took Sans’s shoulder and pulled him aside, “HOW ARE YOU DOING SANS?”  
Sans’s eyes darkened a bit, “I can still feel her presence, I feel like she’s silently judging me for being a terrible parent.” He chuckled dryly the sighed. “Nah, that’s not fair of me to say, she knows I’m doing my best.”  
Papyrus nodded, “IT’S ALRIGHT SANS,” He smiled happily. “BUT THERE IS NO BETTER PARENT THAN MY BROTHER!”  
Undyne walked up to them and she wrapped an arm around Sans’s shoulders, “Yeah, ya bonehead! You think the shrimp’s getting all his awesome traits from us? Well, he might’ve picked up a few from me.”  
Sans looked at his son bouncing on the couch, his blue irises bright and happy. He looked back to his brother and then to Undyne, his smile went watery, “Heh…I guess you’re right.”  
Papyrus smiled and held out his arms for Sans. Sans hugged him, “THIS NEW FORM OF YOURS IS STILL STRANGE TO ME, YOU AREN’T SHORT AND YOU ACT MORE…WELL, YOU’RE MORE ACTIVE THAN BEFORE.”  
Sans pulled away and shrugged, “I’m still me Pap,” he chuckled and wiped his eyes a bit. “Still your big brother.”  
Undyne looked Sans over, “Yeah, I’m still getting used to seeing you all…purple and black.”  
Sans frowned at her, “Hey, purple is an incredible color.”  
She folded her arms, “Not going to deny that.” She gave him a toothy grin.  
Papyrus shrugged, “I LOVE ALL COLORS!”  
Sans chuckled, “Yeah…” He blushed and sighed. “This doesn’t get easier, does it?”  
Undyne gave him a nudge, “Of course it does…right?” She nudged Papyrus.  
Papyrus nodded, “YES, IT GETS EASIER.” He set a hand on his brother’s shoulder. “WORRY NOT BROTHER!”  
Sans nodded and looked back at Aiden who was peeking over the couch at him. He smiled at him and Aiden smiled back. He chuckled and turned back to Papyrus, “You guys ready to watch some anime?”

Halfway through the show Sans noticed Aiden kept looking over at him as though he were contemplating doing something but didn’t know what to do with himself. Sans glanced down every now and again to see him looking more and more frustrated. Sans was about to ask him if he was okay when Aiden crawled into Sans’s lap and snuggled comfortably against him. Pure happiness ran through him at that moment.  
“You alright, Aiden?”  
“HE LOOKS SLEEPY!” Papyrus said smiling over at him.  
Sans chuckled, “You sleepy, kiddo?”  
Aiden nodded slowly and rubbed his eye, yawning a bit before nuzzling deeper into Sans’s jacket. Sans felt like his chest was throbbing with love, “Alright, you take a nap, I’ll be right here.” He murmured as he stroked Aiden’s black curls. He watched his son close his eyes and in seconds he was asleep. Sans spent an hour like that, watching over and smoothing his son’s hair while he slept. He looked so much like his mother…  
The others couldn’t help glancing over at Sans and Aiden, the sight of them was too cute for words. Mettaton leaned into Papyrus, “I’m a little shocked at your brother, darling. He’s making me want one.”  
Papyrus had been drinking water when he suddenly choked. Undyne patted his back, “You okay?” She asked over his shoulder. “You should slow down on the water there, Papyrus.”  
Papyrus’s face was red and his eyes were averted. Mettaton laughed at him, “I’m only kidding dear, don’t look so shell shocked.”  
Sans snorted, “Good one.”  
Mettaton rolled his eyes, “That wasn’t a pun, Sans.”  
Sans shrugged, “If you say so.”  
Alphys leaned on Undyne and smiled, “I think kids are a h-handful.”  
Sans leaned on his arm, “It has its ups and downs, Aiden’s smart and adventurous like his mom. But he doesn’t give me too much trouble…though, in the first five months he was born was a living hell.” Sans chuckled. “Keeping me up to feed or change him in the middle of the night.”  
Papyrus nodded, “AH YES HE KEPT US ALL AWAKE MOST NIGHTS.”  
Sans shrugged and smiled down at the child curled up against him, “Was worth it.”  
Undyne grinned, “I can’t wait for the squirt to start using magic! Training is going to be so much fun! When I’m through with him he’ll be a fu-“  
“Watch your mouth.” Sans said glancing at her.  
“FUN! He’ll be a fun little sparring partner.” She finished with a nervous laugh.  
Sans chuckled, “I’m sure he will be.”


End file.
